extra

parse extra arguments to a command after "--"

Ever want to create a command that spawned another command, and let the user pass arguments and environment variables to it?
extra modifies process.argv and parses out command/arguments/etc passed after -- in the argument list, which enables you to spawn a separate command with the result, and still use commander.js or other "strict" argument checking libraries which would normally complain about unknown arguments.

Usage

var extra = require('extra')
  , cmd = require('commander')
  , spawn = require('child_process').spawn

var e = extra();
cmd.parse(process.argv);
if (cmd.args[0] === 'spawn') {
  spawn(e.cmd, e.args, {env: e.env});
}

Example

Use extra() to spawn an arbitrary command with user-specified options.

#!/usr/bin/env node
var extra = require('extra')
  , program = require('commander')
  , spawn = require('child_process').spawn

var e = extra();

program
  .command('spawn')
  .usage('[options] -- <cmd> [cmd_options] [cmd_args...]')
  .option('--fork', 'fork the process and exit')
  .action(function (cmd) {
    var proc = spawn(e.cmd, e.args, {env: e.env});
    if (cmd.fork) {
      process.exit();
    }
    proc.stdout.pipe(process.stdout);
    proc.stderr.pipe(process.stderr);
    process.on('exit', function () {
      proc.kill();
    });
  })

program.parse(process.argv);

if (!program.args.length) program.outputHelp();

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Developed by Terra Eclipse

Terra Eclipse, Inc. is a nationally recognized political technology and strategy firm located in Aptos, CA and Washington, D.C.

• • -

License: MIT

• Copyright (C) 2013 Carlos Rodriguez (http://s8f.org/)
• Copyright (C) 2013 Terra Eclipse, Inc. (http://www.terraeclipse.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.